While substantial effort and attention continues toward the development of newer and more sustainable energy supplies, the conservation of energy by increased energy efficiency remains crucial to the world's energy future. According to an October 2010 report from the U.S. Department of Energy, heating and cooling account for 56% of the energy use in a typical U.S. home, making it the largest energy expense for most homes. Along with improvements in the physical plant associated with home heating and cooling (e.g., improved insulation, higher efficiency furnaces), substantial increases in energy efficiency can be achieved by better control and regulation of home heating and cooling equipment. By activating heating, ventilation, and air conditioning (HVAC) equipment for judiciously selected time intervals and carefully chosen operating levels, substantial energy can be saved while at the same time keeping the living space suitably comfortable for its occupants.
Programmable thermostats have become more prevalent in recent years in view of Energy Star (US) and TCO (Europe) standards, and which have progressed considerably in the number of different settings for an HVAC system that can be individually manipulated. Some programmable thermostats have standard default programs built in. Additionally, users are able to adjust the manufacturer defaults to optimize their own energy usage. Ideally, a schedule is used that accurately reflects the usual behavior of the occupants in terms of sleeping, waking and periods of non-occupancy. Due to difficulty in programming many thermostats, however, may schedules do not accurately reflect the usual behavior of the occupants. For example, the schedule may not account for some usual periods of non-occupancy. Additionally, even when a suitable schedule is programmed into the thermostat, inevitably there are departures from usual behavior. The user can manually set back the thermostat when leaving the house and then resume the schedule upon returning, but many users never or very seldom perform these tasks. Thus an opportunity for energy and cost savings exist if a thermostat can automatically set back the setpoint temperature during time of non-occupancy.
U.S. Patent Application Publication No. 2010/0019051 A1 discusses overriding of nonoccupancy status in a thermostat device based upon analysis or recent patterns of occupancy. The publication discusses a “safety time,” for example during the nighttime hours in a hotel or motel room, during which requirements to maintain a condition of occupancy are relaxed based on pattern recognition analysis. A “hysteresis” period of typically less than a few minutes can be built into the motion sensor to establish occupancy for some period after any motion is detected or signaled. An increased hysteresis period can be used during safety times such as during the evening and night hours. The focus is mainly on reliably detecting when occupants return from an absence.
Important issues arise, however, at the interface between (i) energy-saving technologies that might be achievable using known sensing and processing methods, and (ii) the actual widespread user adoption of devices that implement such energy-saving technologies and the integration of those devices into their daily routines and environment. It has been found especially important that the “first contact” between a user and an energy-saving device, and the first couple of days/weeks of the user experience with that energy-saving device, constitute a particularly easy, enjoyable, and pleasant experience, or else the user can quickly “turn off” or “tune out” to the device and its energy-saving advantages, such as by de-activating the advanced features (for example, setting their thermostat to a “temporary” manual-override mode on a permanent basis) or even taking it back to the seller and replacing it with their old device or a “less complicated” device. More bluntly stated, the roadways of green technology are littered with the skulls of devices and systems that promised to save energy but that no homeowners wanted to use. One or more issues arises in the context of providing an intelligent, multi-sensing, network-connected, energy-saving device for adoption into the home in an easy, pleasant, and user-friendly manner that is at least partially addressed by one or more of the embodiments described further hereinbelow. Other issues arise as would be apparent to a person skilled in the art in view of the present teachings.